CVE-2024-45538: Synology DiskStation Manager CSRF Vulnerability

CVE-2024-45538 Overview

A critical Cross-Site Request Forgery (CSRF) vulnerability has been identified in the WebAPI Framework component of Synology DiskStation Manager (DSM) and Synology Unified Controller (DSMUC). This vulnerability allows remote attackers to execute arbitrary code by tricking authenticated users into making unintended requests to the vulnerable application. The flaw exists in versions of DSM before 7.2.1-69057-2 and 7.2.2-72806, as well as DSMUC before 3.1.4-23079.

Critical Impact

Remote attackers can leverage this CSRF vulnerability to execute arbitrary code on affected Synology NAS devices, potentially leading to complete system compromise, data theft, or ransomware deployment on network-attached storage systems containing sensitive data.

Affected Products

• Synology DiskStation Manager (DSM) versions before 7.2.1-69057-2
• Synology DiskStation Manager (DSM) versions before 7.2.2-72806
• Synology Unified Controller (DSMUC) versions before 3.1.4-23079

Discovery Timeline

• 2025-12-04 - CVE-2024-45538 published to NVD
• 2025-12-05 - Last updated in NVD database

Technical Details for CVE-2024-45538

Vulnerability Analysis

This vulnerability stems from inadequate CSRF protections in the WebAPI Framework used by Synology's DiskStation Manager. The WebAPI Framework serves as the backbone for management operations on Synology NAS devices, handling authentication, configuration changes, and system administration tasks.

When a user is authenticated to the DSM web interface, the application fails to properly validate the origin of state-changing requests. An attacker can craft a malicious webpage containing requests that, when visited by an authenticated DSM administrator, will be automatically executed with the victim's privileges. Due to the scope change indicated in the vulnerability assessment, exploitation can impact resources beyond the vulnerable component itself.

The attack requires user interaction—specifically, the victim must visit a malicious page or click a crafted link while authenticated to their Synology device. However, given that many users maintain persistent sessions to their NAS devices, this attack surface is readily exploitable.

Root Cause

The root cause is classified under CWE-352 (Cross-Site Request Forgery). The WebAPI Framework in affected DSM versions does not implement sufficient anti-CSRF mechanisms such as:

• Missing or improperly validated CSRF tokens on state-changing API endpoints
• Lack of same-site cookie attributes
• Insufficient origin header validation

This allows attackers to forge requests that appear legitimate to the server when originating from a victim's authenticated browser session.

Attack Vector

The attack is network-based and requires user interaction. An attacker would typically:

1. Identify a vulnerable Synology DSM instance accessible to the target user
2. Craft a malicious webpage containing forged requests to the DSM WebAPI
3. Distribute the malicious page via phishing emails, compromised websites, or social engineering
4. When an authenticated DSM user visits the malicious page, the forged requests execute with their privileges
5. The attacker achieves arbitrary code execution on the NAS device

The vulnerability is particularly dangerous in enterprise environments where Synology NAS devices often contain critical business data and may have elevated network privileges. Successful exploitation could lead to data exfiltration, ransomware deployment, or lateral movement within the network.

Detection Methods for CVE-2024-45538

Indicators of Compromise

• Unexpected configuration changes on Synology DSM devices without corresponding administrator activity
• Unusual scheduled tasks or scripts appearing on NAS devices
• Unexpected user accounts or permission changes in DSM
• Web server logs showing requests to DSM WebAPI endpoints with external referrer headers

Detection Strategies

• Monitor DSM audit logs for administrative actions that don't correlate with known user activity
• Implement network monitoring to detect unusual traffic patterns to Synology devices
• Deploy web application firewall rules to detect potential CSRF attack patterns
• Enable and review access logs for DSM web interfaces

Monitoring Recommendations

• Configure alerting for any DSM configuration changes outside maintenance windows
• Monitor for new scheduled tasks or package installations on NAS devices
• Implement egress filtering to detect potential data exfiltration from NAS systems
• Review authentication logs for session anomalies

How to Mitigate CVE-2024-45538

Immediate Actions Required

• Upgrade Synology DiskStation Manager to version 7.2.1-69057-2 or later immediately
• For DSM 7.2.2 branch, upgrade to version 7.2.2-72806 or later
• Upgrade Synology Unified Controller to version 3.1.4-23079 or later
• Restrict DSM web interface access to trusted networks only until patching is complete
• Review recent administrative changes on all Synology devices for signs of compromise

Patch Information

Synology has released security patches addressing this vulnerability. Detailed information is available in Synology Security Advisory SA-24-27. Administrators should apply the appropriate update based on their DSM version:

• DSM 7.2.1: Update to 7.2.1-69057-2 or later
• DSM 7.2.2: Update to 7.2.2-72806 or later
• DSMUC: Update to 3.1.4-23079 or later

Updates can be applied through the DSM Control Panel under "Update & Restore" or via the Synology Download Center.

Workarounds

• Restrict access to the DSM web interface to internal networks only using firewall rules
• Implement strict browser security practices—users should not browse untrusted websites while authenticated to DSM
• Consider disabling external DSM access via QuickConnect or port forwarding until patches are applied
• Enable two-factor authentication on all DSM accounts to add an additional security layer

# Example: Restrict DSM access to internal network using iptables
# Apply on your network firewall/router to limit access to Synology devices

# Allow internal network access to DSM (port 5000/5001)
iptables -A INPUT -p tcp -s 192.168.1.0/24 --dport 5000 -j ACCEPT
iptables -A INPUT -p tcp -s 192.168.1.0/24 --dport 5001 -j ACCEPT

# Drop external access to DSM ports
iptables -A INPUT -p tcp --dport 5000 -j DROP
iptables -A INPUT -p tcp --dport 5001 -j DROP